Display panel or portion thereof with a transitional graphical user interface



FIG. 1 is a first image in a sequence for a display panel or portion thereof with a transitional graphical user interface, showing the new design.

FIG. 2 is a second image in a sequence for a display panel or portion thereof with a transitional graphical user interface, showing the new design.

FIG. 3 is a third image in a sequence for a display panel or portion thereof with a transitional graphical user interface, showing the new design.

FIG. 4 is a fourth image in a sequence for a display panel or portion thereof with a transitional graphical user interface, showing the new design; and,

FIG. 5 is a fifth image in a sequence for a display panel or portion thereof with a transitional graphical user interface, showing the new design.

The broken lines showing a front of a device housing, of the display panel, and of elements, indicia, and words within the display panel, are for environmental purposes only and form no part of the claimed design.

The appearance of the image sequentially transitions between the images shown in FIGS. 1-5. The process or period in which one image transitions to another image forms no part of the claimed design. 

CLAIM What is claimed is the ornamental design for a display panel or portion thereof with transitional graphical user interface, as shown and described. 